Layered control panel design to provide separation of high/low voltage

ABSTRACT

A layered control panel for a heating, ventilation, air conditioning, and refrigeration (HVACR) unit includes an outer layer on which low-voltage components are placed, and an inner layer on which high-voltage components are placed. The outer layer is capable of taking a closed position where it blocks access to the inner layer, and an open position where the outer layer does not block access to the inner layer. The outer layer can include a lock to keep the outer layer in the closed position. The outer layer can be one or two or more panels mounted on hinges that allow the outer layer to swing between closed and open positions.

FIELD

This disclosure is directed to control panels for heating, ventilation,air conditioning, and refrigeration (HVACR) units, particularly controlpanels separating high and low-voltage controls.

BACKGROUND

Control panels for heating, ventilation, air conditioning, andrefrigeration (HVACR) units typically include low-voltage componentsalongside high-voltage components. High-voltage components typically arevery restrictive with respect to servicing, often requiring unitshutdown, servicers wearing protective equipment, and/or othersignificant steps to be safely serviced. Current control panels canprovide high-voltage components in a region of the panel that can beprotected by their own compartment having a separate door, but this isspace-inefficient, particularly relative to the limited space in whichcontrol panels can be provided on some HVACR units.

SUMMARY

This disclosure is directed to control panels for heating, ventilation,air conditioning, and refrigeration (HVACR) units, particularly controlpanels separating high and low-voltage controls.

Layered control panels according to embodiments can effectively separatelow-voltage components from high-voltage components, while takingadvantage of the layering to be space-efficient. Low-voltage componentscan be provided on an outer layer so that they can be accessed readily,while high-voltage components are provided on an inner layer which istypically covered by the outer layer, restricting access to thehigh-voltage components. The layered design allows the same surface areato be used for each set of components, while the order of the layeringfacilitates servicing of low-voltage components while restricting accessto high-voltage components. Further, this arrangement allows the HVACRunit to continue to be operated during servicing of the low-voltagecomponents, facilitating diagnosis of some potential issues andstreamlining troubleshooting processes.

In an embodiment, a control panel for a heating, ventilation, airconditioning, and refrigeration (HVACR) unit includes a control panelhousing having an open side, an inner layer disposed within the controlpanel housing, a plurality of high-voltage components disposed on theinner layer, an outer layer disposed closer to the open side of thecontrol panel housing, and a plurality of low-voltage componentsdisposed on the outer layer. The outer layer is configured to be movablebetween a closed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing and an open position where the plurality of high-voltagecomponents are accessible through the open side of the control panelhousing. The high-voltage components are disposed only on the innerlayer.

In an embodiment, the low-voltage components are safety extra-lowvoltage (SELV) components.

In an embodiment, the outer layer comprises a single piece. In anembodiment, the control panel further includes a hinge on a first sideof the single piece of the outer layer, the hinge connecting the singlepiece of the outer layer to the control panel housing. In an embodiment,the control panel further includes a lock on a second side of the singlepiece of the outer layer, the second side opposite the first side.

In an embodiment, the outer layer comprises a plurality of pieces. In anembodiment, each of the plurality of pieces includes a hinge, the hingeconnecting the piece to the control panel housing. In an embodiment, atleast two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position. In anembodiment, some of the plurality of low-voltage components are disposedon each of the plurality of pieces. In an embodiment, the low-voltagecomponents are disposed on only one of the plurality of pieces.

In an embodiment, a heating, ventilation, air conditioning, andrefrigeration (HVACR) unit includes a control panel disposed on anexterior surface of the HVACR unit. The control panel includes a controlpanel housing having an open side, an inner layer disposed within thecontrol panel housing, a plurality of high-voltage components disposedon the inner layer, an outer layer disposed closer to the open side ofthe control panel housing, and a plurality of low-voltage componentsdisposed on the outer layer. The outer layer is configured to be movablebetween a closed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing and an open position where the plurality of high-voltagecomponents are accessible through the open side of the control panelhousing. The high-voltage components are disposed only on the innerlayer.

In an embodiment, the low-voltage components are safety extra-lowvoltage (SELV) components.

In an embodiment, the outer layer comprises a single piece. In anembodiment, the control panel further includes a hinge on a first sideof the single piece of the outer layer, the hinge connecting the singlepiece of the outer layer to the control panel housing. In an embodiment,the control panel further includes a lock on a second side of the singlepiece of the outer layer, the second side opposite the first side.

In an embodiment, the outer layer comprises a plurality of pieces. In anembodiment, each of the plurality of pieces includes a hinge, the hingeconnecting the piece to the control panel housing. In an embodiment, atleast two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position. In anembodiment, some of the plurality of low-voltage components are disposedon each of the plurality of pieces. In an embodiment, the low-voltagecomponents are disposed on only one of the plurality of pieces.

DRAWINGS

FIG. 1 shows a perspective view of a control panel according to anembodiment, where the doors carrying low-voltage components are open.

FIG. 2A shows a front view of the control panel shown in FIG. 1, whenthe outer layer carrying low-voltage components is closed.

FIG. 2B shows a front view of the control panel shown in FIG. 1, whenthe outer layer carrying low-voltage components is open.

FIG. 3 shows a heating, ventilation, air conditioning, and refrigerationsystem including a control panel according to an embodiment.

DETAILED DESCRIPTION

This disclosure is directed to control panels for heating, ventilation,air conditioning, and refrigeration (HVACR) units, particularly controlpanels separating high and low-voltage controls.

FIG. 1 shows a perspective view of a control panel according to anembodiment, where the layer carrying low-voltage components is open.Control panel 100 includes control panel housing 102 having an open side104, an outer layer 106 including first outer layer portion 108, andsecond outer layer portion 110, a first hinge 112, a second hinge 114,low-voltage components 116, inner layer 118, and high-voltage components120. Housing support 122 is provided in the control panel housing 102,between the inner layer 118 and the open side 104, when the inner layer118 is in a closed position.

Control panel housing 102 is a housing configured to contain one or morecomponents such as controls, including low-voltage components 116 andhigh-voltage components 120. Control panel housing 102 can protect itscontents from an exterior environment and/or from unauthorized access.Control panel housing 102 can include one or more walls defining aperimeter of a shape and providing an open side 104. The control panelhousing 102 can be mounted on an HVACR unit, for example being providedon a wall of a cabinet of an HVACR unit such as a side wall of thecabinet.

Open side 104 is defined by the control panel housing 102. Open side 104of the control panel housing 102 can be sized and positioned in order toaccess to at least some of the contents of control panel housing 102.The open side 104 can be sized and positioned to allow at least theportion of the contents of control panel housing 102 to be accessed forservicing, for example being sized to allow hands and tools ofmaintenance personnel to reach into the control panel housing 102.

Outer layer 106 includes one or more panels. Outer layer 106 isconfigured to be movable between a closed position and an open position.In an embodiment, outer layer 106 is movable between the closed positionand the open position by moving each of the one or more panels formingouter layer 106. The one or more panels of the outer layer can each berotatable about hinges to move between the closed and open positions.When outer layer 106 is in a closed position, outer layer 106 is in aspace between the open side 104 and the inner layer 118, such that theouter layer 106 can be accessed through the open side 104, but outerlayer 106 is positioned such that it obstructs access to inner layer118. Outer layer 106 can have one or more low-voltage components 116located on its surfaces. In an embodiment, low-voltage components 116are located only on the outer layer 106 and are not, for example,included on inner layer 118. In an embodiment, the low-voltagecomponents 116 are provided on the outer layer 106 such that they can beaccessed for operation or maintenance when the outer layer 106 is in theclosed position. In an embodiment, the outer layer 106 is a continuouslayer when in the closed position, including either one portion ormultiple portions that connect to one another. In an embodiment, theouter layer 106 includes one or more portions, where at least some ofthe portions of outer layer 106 connect to the housing support 122 whenouter layer 106 is in the closed position. In the embodiment shown inFIG. 1, outer layer 106 includes first outer layer portion 108 andsecond outer layer portion 110.

First outer layer portion 108 is one of the panels that forms a part ofouter layer 106. First outer layer portion 108 can be joined to thecontrol panel housing 102 by way of first hinge 112. First outer layerportion 108 can be any suitable material for a panel supportinglow-voltage components 116. First outer layer portion 108 can include atleast some of the low-voltage components 116 included in control panel100. In an embodiment, first outer layer portion 108 includes one ormore retention features 124 such that it can be secured to another part,such as second outer layer portion 110 or housing support 122. In anembodiment, the first outer layer portion 108 can be secured to thehousing support 122 when the first outer layer portion 108 is in theclosed position for outer layer 106.

Second outer layer portion 110 is another panel forming a part of outerlayer 106. Second outer layer portion 110 can be joined to the controlpanel housing 102 by way of second hinge 114. Second outer layer portion110 can be any suitable material for a panel supporting low-voltagecomponents 116. Second outer layer portion 110 can include at least someof the low-voltage components 116 included in control panel 100. In anembodiment, second outer layer portion 110 includes one or moreretention features 124 such that it can be secured to another part, suchas first outer layer portion 108 or housing support 122. In anembodiment, the second outer layer portion 110 can be secured to thehousing support 122 when the second outer layer portion 110 is in theclosed position for outer layer 106.

Low-voltage components 116 are electronic components such as controlsfor the HVACR system. Low-voltage components 116 can be electroniccomponents that can be safe to access, operate, or service without riskto personnel. In an embodiment, the low-voltage components 116 can besafe to access, operate, or service without requiring personnel to beequipped with personal protective equipment. Low-voltage components 116can include, for example, any suitable separated or safetyextra-low-voltage (SELV) components for the HVACR system includingcontrol panel 100. The classification of low-voltage components 116 asSELV components can be performed according to any suitable standards forsuch status, such as defined installation standards. An example of sucha standard is UL60335-1. In an embodiment, all of the low-voltagecomponents 116 included in control panel 100 can be provided only on theouter layer 106 such that the low-voltage components 116 can be operatedor serviced while the outer layer is in the closed position. Low-voltagecomponents 116 can be provided on any one or more portions of the outerlayer 106. In an embodiment, low-voltage components 116 are provided oneach of the portions making up outer layer 106. Non-limiting examples oflow-voltage components include programmable logic controllers,communication modules, controller-to-harness interface circuits, extralow voltage distribution terminal blocks, and the like.

Inner layer 118 is a panel or support configured to support high-voltagecomponents 120. In an embodiment, inner layer 118 can be positionedwithin control panel housing 102 such that it is further from the openside 104 than the outer layer 106 at least when the outer layer 106 isin the closed position. Inner layer 118 can be positioned further fromthe open side 104 than an outermost portion of housing support 122 whena housing support 122 is included in control panel 100. The inner layer118 can be any suitable material for a panel supporting high-voltagecomponents 120. In an embodiment, all high-voltage components 120included in control panel 100 are located on inner layer 118. In anembodiment, no low-voltage components 116 are located on inner layer118.

In an embodiment, inner layer 118 can be opposite sides of some or allof the panels defining outer layer 106, such as first outer layerportion 108 and second outer layer portion 110. In this embodiment,inner layer 118 is provided inside the control panel housing 102 whenthe first outer layer 106 is in the closed position.

High-voltage components 120 are provided on inner layer 118. Thehigh-voltage components are electrical and electronic components such ascontrols of the HVACR system included in control panel 100. Thehigh-voltage components can be components that can pose risk topersonnel accessing, operating, or servicing those components ifenergized during servicing. In an embodiment, the high-voltagecomponents 120 can be the components that require lockout and/or tag-outprocedures to be followed during servicing. The high-voltage components120 can be components receiving power at voltages in excess of safestandards, such as components that do not comply with SELV standards. Asdescribed above, components can be identified as SELV using a suitablestandard, such as standard UL60335-1. The high-voltage components 120can be components requiring personal protective equipment to be wornwhen accessing, operating, or servicing those components. Thehigh-voltage components 120 can be positioned on inner layer 118 suchthat they cannot be accessed through open side 104 when the outer layer106 is in the closed position. The high-voltage components 120 can bepositioned on inner layer 118 such that they can be accessed, operated,and/or serviced when outer layer 106 is not in the closed position, forexample by being accessible through open side 104 when the outer layer106 is in the open position. Non-limiting examples of high-voltagecomponents include power distribution blocks, fuse blocks, contactors,circuit breakers, transformers, overload relays, and the like.

Housing support 122 can optionally be included within control panelhousing 102. Housing support 122 can be a structural feature such as acolumn, a horizontal bar, divider, or other suitable feature providedwithin control panel housing 102. Housing support 122 can be configuredto be contacted by portions of outer layer 106 when outer layer 106 isin the closed position. Housing support 122 can contribute to outerlayer 106 obstructing access to high-voltage components 120 when theouter layer 106 is in the closed position.

Retention features 124 can be provided on outer layer 106 and/or thecontrol panel housing 102 or optional housing support 122. The retentionfeatures 124 are configured to allow outer layer 106 to be retained inthe closed position. The retention features 124 can be any suitablestructures for retaining the outer layer 106 such as flanges, slots,tabs, latches, snap-fit features, hooks, or any corresponding features.In an embodiment, retention features 124 can be provided, for example,on first outer layer portion 108, second outer layer 110, and housingsupport 122. In this embodiment, the retention features 124 can bepositioned and/or configured such that first outer layer portion 108 canbe retained to housing support 122 at one position and second outerlayer portion 110 can be retained to housing support 122 in anotherposition. In another embodiment, retention features 124 can beconfigured to retain first outer layer portion 108 to second outer layerportion 110. In another embodiment, retention features 124 can beconfigured to secure a single piece outer layer 106 to control panelhousing 102. In this embodiment, retention features 124 can beconfigured to secure the single piece outer layer 106 to the controlpanel housing 102 at an end of outer layer 106 opposite where a hingeconnects the outer layer 106 to control panel 102. In an embodiment, theretention features can include a hand- or tool-turnable screw and athreaded hole configured to accommodate the screw. In an embodiment, theopposing retention feature 124 contacted by the screw can be a detentformed in a surface of the control panel housing 102 or outer layerportion 108, 110, depending on where the screw is to be used forretention.

FIG. 2A shows a front view of the control panel 100 shown in FIG. 1,when the outer layer carrying low-voltage components is closed. As canbe seen in the view shown in FIG. 2A, each of first outer layer portion108 and second outer layer portion 110 are rotated about first andsecond hinges 112, 114 such that they extend inwards from control panelhousing 102 towards housing support 112. Each of first outer layerportion 108 and second outer layer portion 110 are locked to housingsupport 122 by their respective retention features 124. Thus, thelow-voltage components 116 are accessible through the open side 104 ofcontrol panel housing 102, while outer layer 106 is positioned betweenthe open side 104 of control panel housing 102 and the inner layer 118.The high-voltage components 120 are inaccessible from open side 104 whenthe outer layer 106 is in the closed position shown in FIG. 2A.

The closed position shown in FIG. 2A can be a standard position for theouter layer 106 during normal operations and servicing of the controlpanel 100. Since only low-voltage components 116 are accessible in theclosed position shown in FIG. 2A, those components can be serviced orotherwise manipulated without requiring shutdown of the HVACR unitincluding control panel 100 or personnel donning electrical personalprotective equipment. The retention features 124 retain the outer layer106 in the position where it obstructs access to the high-voltagecomponents 120. When retention features 124 are disengaged, the firstportion 108 and second portion 110 of outer layer 106 can each be movedto place the control panel 100 into the open position shown in FIG. 2B

FIG. 2B shows a front view of the control panel 100 shown in FIG. 1,when the outer layer 106 carrying low-voltage components is open. Theopen position shown in FIG. 2B can be achieved by releasing anyretention features 124 and moving outer layer 106, for example byrotating first portion 108 about first hinge 112 and rotating secondportion 110 about second hinge 114. In the open position, the innerlayer 118 and the high-voltage components 120 can be accessed throughthe open side 104 of control panel housing 102. In an embodiment thehousing support 122 can still be located between a portion of open side104 and the inner layer 118. In an embodiment, the high-voltagecomponents 120 can be disposed on inner layer 118 such that access tothe high-voltage components 120 is not obstructed by housing support122. In an embodiment, the open position of FIG. 2B can be takenfollowing lockout and/or tag-out procedures for the servicing ofhigh-voltage components 120.

FIG. 3 shows a heating, ventilation, air conditioning, and refrigeration(HVACR) system including a control panel according to an embodiment.HVACR system 300 includes cabinet 302 having side walls 304, and acontrol panel 306 provided on a surface of one of the side walls 304.Cabinet 302 is a structure containing at least some components of theHVACR system 300, such as, as non-limiting examples, air handlingblowers, outdoor coils, compressors, or any other suitable HVACR systemcomponent. Side walls 304 define the exterior of the cabinet 302. Thecontrol panel 306 is provided on one of the side walls 304. Controlpanel 306 contains one or more electronic components used to controland/or operate HVACR system 300. The control panel 306 can be thecontrol panel of FIG. 1 or 2A and 2B as described above. In anembodiment, control panel 306 is mounted recessed into the side wall 304such that when it is in the closed position, the outer layer is recessedor flush with respect to side wall 304. In an embodiment, control panel306 projects outwards from side wall 304. Control panel 306 can furtherinclude one or more doors 308. The doors 308 can cover an open side of acontrol panel housing of the control panel 306. When closed, doors 308can obstruct access to an outer layer including low-voltage componentsof control panel 306, such as outer layer 106 of control panel 100 asdescribed above and shown in FIG. 1. In an embodiment, doors 308 formpart of one of side walls 304. In an embodiment, doors 308 can be flushwith side wall 304 that control panel 306 is mounted in.

Aspects:

It is understood that any of aspects 1-10 can be combined with any ofaspects 11-20.

Aspect 1. A control panel for a heating, ventilation, air conditioning,and refrigeration (HVACR) unit, comprising:

a control panel housing having an open side;an inner layer disposed within the control panel housing;a plurality of high-voltage components disposed on the inner layer;an outer layer disposed closer to the open side of the control panelhousing;a plurality of low-voltage components disposed on the outer layer;whereinthe outer layer is configured to be movable between:a closed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing, andan open position where the plurality of high-voltage components areaccessible through the open side of the control panel housing, and thehigh-voltage components are disposed only on the inner layer.

Aspect 2. The control panel according to aspect 1, wherein thelow-voltage components are safety extra-low voltage (SELV) components.

Aspect 3. The control panel according to any of aspects 1-2, wherein theouter layer comprises a single piece.

Aspect 4. The control panel according to aspect 3, further comprising ahinge on a first side of the single piece of the outer layer, the hingeconnecting the single piece of the outer layer to the control panelhousing.

Aspect 5. The control panel according to aspect 4, further comprising alock on a second side of the single piece of the outer layer, the secondside opposite the first side.

Aspect 6. The control panel according to any of aspects 1-2 wherein theouter layer comprises a plurality of pieces.

Aspect 7. The control panel according to aspect 6, wherein each of theplurality of pieces includes a hinge, the hinge connecting the piece tothe control panel housing.

Aspect 8. The control panel according to any of aspects 6-7, wherein atleast two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position.

Aspect 9. The control panel according to any of aspects 6-8, whereinsome of the plurality of low-voltage components are disposed on each ofthe plurality of pieces.

Aspect 10. The control panel according to any of aspects 6-8, whereinthe low-voltage components are disposed on only one of the plurality ofpieces.

Aspect 11. A heating, ventilation, air conditioning, and refrigeration(HVACR) unit, comprising a control panel disposed on an exterior surfaceof the HVACR unit, the control panel comprising:

a control panel housing having an open side;an inner layer disposed within the control panel housing;a plurality of high-voltage components disposed on the inner layer;an outer layer disposed closer to the open side of the control panelhousing;a plurality of low-voltage components disposed on the outer layer;wherein:the outer layer is configured to be movable between:a closed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing, andan open position where the plurality of high-voltage components areaccessible through the open side of the control panel housing, andthe high-voltage components are disposed only on the inner layer.

Aspect 12. The HVACR unit according to aspect 11, wherein thelow-voltage components are safety extra-low voltage (SELV) components.

Aspect 13. The HVACR unit according to any of aspects 11-12, wherein theouter layer comprises a single piece.

Aspect 14. The HVACR unit according to aspect 13, further comprising ahinge on a first side of the single piece of the outer layer, the hingeconnecting the single piece of the outer layer to the control panelhousing.

Aspect 15. The HVACR unit according to aspect 14, further comprising alock on a second side of the single piece of the outer layer, the secondside opposite the first side.

Aspect 16. The HVACR unit of according to any of aspects 11-12, whereinthe outer layer comprises a plurality of pieces.

Aspect 17. The HVACR unit according to aspect 16, wherein each of theplurality of pieces includes a hinge, the hinge connecting the piece tothe control panel housing.

Aspect 18. The HVACR unit according to any of aspects 16-17, wherein atleast two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position.

Aspect 19. The HVACR unit according to any of aspects 16-18, whereinsome of the plurality of low-voltage components are disposed on each ofthe plurality of pieces.

Aspect 20. The HVACR unit according to any of aspects 16-18, wherein thelow-voltage components are disposed on only one of the plurality ofpieces.

The examples disclosed in this application are to be considered in allrespects as illustrative and not limitative. The scope of the inventionis indicated by the appended claims rather than by the foregoingdescription; and all changes which come within the meaning and range ofequivalency of the claims are intended to be embraced therein.

1. A control panel for a heating, ventilation, air conditioning, andrefrigeration (HVACR) unit, comprising: a control panel housing havingan open side; an inner layer disposed within the control panel housing;a plurality of high-voltage components disposed on the inner layer; anouter layer disposed closer to the open side of the control panelhousing; a plurality of low-voltage components disposed on the outerlayer; wherein: the outer layer is configured to be movable between: aclosed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing, and an open position where the plurality of high-voltagecomponents are accessible through the open side of the control panelhousing, and the high-voltage components are disposed only on the innerlayer.
 2. The control panel of claim 1, wherein the low-voltagecomponents are safety extra-low voltage (SELV) components.
 3. Thecontrol panel of claim 1, wherein the outer layer comprises a singlepiece.
 4. The control panel of claim 3, further comprising a hinge on afirst side of the single piece of the outer layer, the hinge connectingthe single piece of the outer layer to the control panel housing.
 5. Thecontrol panel of claim 4, further comprising a lock on a second side ofthe single piece of the outer layer, the second side opposite the firstside.
 6. The control panel of claim 1, wherein the outer layer comprisesa plurality of pieces.
 7. The control panel of claim 6, wherein each ofthe plurality of pieces includes a hinge, the hinge connecting the pieceto the control panel housing.
 8. The control panel of claim 6, whereinat least two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position.
 9. Thecontrol panel of claim 6, wherein some of the plurality of low-voltagecomponents are disposed on each of the plurality of pieces.
 10. Thecontrol panel of claim 6, wherein the low-voltage components aredisposed on only one of the plurality of pieces.
 11. A heating,ventilation, air conditioning, and refrigeration (HVACR) unit,comprising a control panel disposed on an exterior surface of the HVACRunit, the control panel comprising: a control panel housing having anopen side; an inner layer disposed within the control panel housing; aplurality of high-voltage components disposed on the inner layer; anouter layer disposed closer to the open side of the control panelhousing; a plurality of low-voltage components disposed on the outerlayer; wherein: the outer layer is configured to be movable between: aclosed position where the outer layer covers the plurality ofhigh-voltage components with respect to the open side of the controlpanel housing, and an open position where the plurality of high-voltagecomponents are accessible through the open side of the control panelhousing, and the high-voltage components are disposed only on the innerlayer.
 12. The HVACR unit of claim 11, wherein the low-voltagecomponents are safety extra-low voltage (SELV) components.
 13. The HVACRunit of claim 11, wherein the outer layer comprises a single piece. 14.The HVACR unit of claim 13, further comprising a hinge on a first sideof the single piece of the outer layer, the hinge connecting the singlepiece of the outer layer to the control panel housing.
 15. The HVACRunit of claim 14, further comprising a lock on a second side of thesingle piece of the outer layer, the second side opposite the firstside.
 16. The HVACR unit of claim 11, wherein the outer layer comprisesa plurality of pieces.
 17. The HVACR unit of claim 16, wherein each ofthe plurality of pieces includes a hinge, the hinge connecting the pieceto the control panel housing.
 18. The HVACR unit of claim 16, wherein atleast two of the plurality of pieces are configured to be locked to ahousing support when the outer layer is in the closed position.
 19. TheHVACR unit of claim 16, wherein some of the plurality of low-voltagecomponents are disposed on each of the plurality of pieces.
 20. TheHVACR unit of claim 16, wherein the low-voltage components are disposedon only one of the plurality of pieces.